The spectrum of wireless network is typically divided into channels with fixed size, which are used for special services, such as the channel for receiving television signals. However, such a division is fixed in time and space dimensions, and some channels with very low utilization rates cannot be utilized by those who lacks channels. This restricts the development of wireless networks.
Thus, there is a phenomenon that PUs (primary users) desire to sell idle channels and SUs (secondary users) desire to buy the idle channels. For this, an effective channel allocation method is needed to ensure that SUs can utilize the idle channels sufficiently without influencing the PUs.